Trouble on vacation

[eracers999]

Left Kansas city for prior lake MN to spend time with the my family and pit for my daughter at elko speedway. I pulled into a car wash, the truck was idleing and it had picked up a new rattle. Hmmm, i crawled all over the thing and it sounded like a loose tork converter. Well i put it together and that would be a first, so i dropped the x over pipe and took down the cover and everything was fine. Hmmm, while it was running i shimmied up the bottom side and got to the front, yeah thats right, that darn lower pully had gone to pot, rubber torchion materiel had separated, got to lookin at that thing and that is really a wierd pully set up. It was sat at 2:30 pm finally found Village chevrolet in wayzata that was open till 4:00 pm and had the part on hand. 155.00 buck's later and some crazy driving from my brother we made it there at 3:50. (boy is MPLS screwed up with road const). Got the pully on and all is well. The main reason for this post is that the pully seems like it would be easy to inspect now that i know what a failed one looks like. If the rubber looks perfect your ok, other wise replace the pully set up, carry a spare or dont get too far from home. Does anyone know how long it will run with the rubber no longer attached?? To those that dont know what im talking about you just have to see one of these things.
Kent

[rjschoolcraft]

Another easy way to tell is if the spokes are rotated relative to the hub. A good pulley has the bolt holes centered between spokes, a bad one, well...

Here are two pictures of my failed unit. Notice the rubber isn't really cracked, but the rim has displaced relative to the hub.

http://www.schoolcraftpowertrain.com/Pictures_&_Data/IM000388.JPG

In the second picture, notice how the "second chance" drive dogs on the spokes have hammered the ends of the slots in the hub.

http://www.schoolcraftpowertrain.com/Pictures_&_Data/IM000389.JPG

This made a terrible racket.

[eracers999]

Ronniejoe:
Nice pics, that is a ruff looking unit. My failed unit is a lot cleaner, you could move the two halfs from one stop to the other with ease. How long do you think that it would run just off the bearing, total rubber failure ?
Kent

[rjschoolcraft]

This one's been lying around for a couple of years, so it's rusted some. This one ran for about 5 months and 17,500 miles before I figured out what was going on.

[Spindrift]

Regarding crank failure...is it more the result of the rubber going bad as opposed to the alignment problem that you experienced?

[rjschoolcraft]

My personal opinion is that the crank pulley failures don't cause crankshaft failures. I think the pulley shown in the article was probably bad, but came completely apart when the crankshaft failed. In otherwords it was secondary to crankshaft failure, not primary. This is my opinion and is not shared by others on this website.

[catmandoo]

thanks for posting this ,i was at a stoplite today with my 94 sub and it had a weird vibration for about 2 seconds then it would quit for 2 seconds then do it again over and over you could feel it in the steering wheel and thru the brake pedal,well got thinking about this post and checked the pulley and sure enough the outer ring is rotated clear over to the bolts,so think its time for the pulley balancer and a timing chain,